April 21, 2025 update

General background: We are a little slow getting off the mark with our updates this year.  The UC ANR web platform was changed in the last month and we're having some issues migrating the old website and blogs over to the new platform.  In the meantime we're using this web hosting platform. 

Thrips development: The first post winter generation adults peaked around the end of March.  Peak egg hatch for generation 2 happened about a week ago, with generation 2 adults peaking around the start of May. We have had a positive confirmation of TSWV from tomato already in Fresno county - about a month ahead of when we typically start to see virus symptoms start to appear.  While this is a worrying report, virus levels in thrips likely remain low for most locations. If you're wondering about when best to apply treatments contact your local UCCE adviser to discuss the specifics of your situation.  Our general advice for now is that targeting generation 3 or 4 is likely to give the best return.  Generation 3 will be developing on plants through May, with adults peaking at the end of May or early June.

Model output: While we work on a new UC ANR website for the thrips model, we've made a simple interface hosted on the third-part web provider Neocities. If you want to see the model output for your region, you can follow the link below.
https://ca-thrips-tswv.neocities.org/models/fresno